Originally Posted by chasbmw
The Brown earth wire that used to go to the level warning light switch on the under tank MC needs to go to ground as it provides a ground path for (some of) the other warning lights in the speedo casing, if a remember correctly this also resulted in the indicators running strangely . It took me a long time to work this out when I fitted the handlebar M/C to my 90/6.
Not to steal Tete's thread, but we are both installing an Acewell, so... Charles, as I look at the wiring schematics, I cannot see why the brown wire needs to be grounded to the frame. I don't doubt your actual experience, but I don't see the necessity of "re-grounding" the brown wire, as it appears that it already goes to ground (again, based on my interpretation the schematics).